For many years, it has been known to dispense liquids, such as soaps, sanitizers, cleansers, disinfectants, and the like from a dispenser housing maintaining a refill unit that holds the liquid and provides the pump mechanisms for dispensing the liquid. The pump mechanism employed with such dispensers has typically been a liquid pump, simply emitting a predetermined quantity of the liquid upon movement of an actuator. Recently, for purposes of effectiveness and economy, it has become desirable is to dispense the liquids in the form of foam, generated by the interjection of air into the liquid. Accordingly, the standard liquid pump has given way to a foam generating pump, which necessarily requires means for combining the air and liquid in such a manner as to generate the desired foam. The concepts taught herein are applicable to both liquid and foam dispensers.
Of particular interest are those dispensers providing a push bar that is pushed from a rest position to an actuated position to actuate the pump mechanism and dispense foam to the operator's hand. Typically the dispensing tube extending from the pump mechanism is stationary and provides an outlet that is distanced from the push bar in its rest position. To dispense liquid, the operator cups his fingers under the outlet of the dispensing tube while pushing the push bar toward the outlet with the base of his palm. This dispenses the liquid through the outlet and onto his hand. This general structure presents some problems for those with small hands, as they may not be large enough to both engage the push bar and register with the outlet. For individuals with small hands, an initial dose of liquid may miss their hand and be dispensed to the floor or their clothing, that is, until their hand aligns under the outlet. For all individuals operating such dispensers, the dose of liquid is dispensed in a line across their hand because their hand moves relative to the outlet as the push bar is moved. In order to place the dose of liquid in a more consistent location on the operator's hand, some dispensers are structured such that the dispensing tube outlet is associated with the push bar to move with the push bar. Examples of such dispensers can be seen in U.S. Pat. Nos. 5,556,005, 5,797,517, 5,992,698, 6,648,179, and 7,198,177. The present invention improves on the general concept of associating the dispensing tube outlet to move with the push bar.
It is well-known in the dispenser arts, particularly in soap and sanitizer dispensers that the dispensers sometimes drip product. When product is dispensed there is typically a continuous stream of product retained a dispensing path, for example, from an outlet valve of the pump to the actual outlet where the product exits the dispenser to fall on an individual's hand. This residual product can drip out of the dispenser and onto the floor under the effect of gravity. This is particularly true for a dispensed foam product, even more particularly a foamed soap or foamed sanitizer, because the multitude of air bubbles within the foam begin to collect, forming larger air bubbles such that the liquid portion of the foam also collects together to form a more readily flowing liquid that can drip out of the dispenser. Thus, there is a need in the art to take measures to ensure that residual product within a dispenser is prevented from dripping out of the dispenser, and particular embodiments of this invention provides structures to achieve such an anti-drip function.